Sitting at his desk in the president's Philadelphia residence, George Washington sketched out a plan for a unique 16-sided barn sometime in the fall of 1792. Pressing presidential business dictated that he could spend little time with such personal matters. Little did he realize that exactly 200 years later, Mount Vernon staff and consultants would undertake a much more deliberate approach to designing a replica of his barn.

In 1991, the W.K. Kellogg Foundation made an unprecedented contribution to the history of Mount Vernon. The Foundation's grant of $1.75 million made possible the addition of a farm site and reconstruction of Washington's unique 16-sided treading barn that would make it possible for visitors around the world to see Washington as he saw himself - as a farmer. The task presented many research challenges; the planning process before construction on the barn began took almost two years.

Although George Washington left behind a great deal of documentation, many questions regarding the construction of his barn remained. Washington's crew of nine slave carpenters and their foreman knew how to put buildings together and thus much is left unstated by Washington. Without the original barn to study - it was torn down about 1875 - historians and architects had to fill in the blanks by studying the only surviving photograph of the barn, existing structures at Mount Vernon, as well as a 120 page research report compiled before the project even began.

The report justified the opinion of consultants that Washington's round barn, built to streamline the grain-threshing process at Mount Vernon, is the best documented American agricultural building of its period. But, how did 40 rafters come together near the conical peak of the roof? How was grain stored in the lower floor octagon? Were the bars in the windows set flush or on the diagonal? What size nails were used to fasten the floorboards? Were the southern yellow pine timbers purchased from Alexandria merchants mill-sawn or pit-sawn?

Washington, his manager, and his carpenters left nary a clue.

The design team on the new barn relied on the only existing photograph of the barn, taken around 1870, to provide many of these details. Using specially-designed software, the image from an original glass slide in the Mount Vernon library was scanned in and manipulated to provide close-ups of critical areas. Siding details, nail patterns, brick coursing, mortar joints, window jamb elements - even confirmation of some interior components - were secured by enhancing the photo.

The exciting discovery of a previously misidentified drawing in Washington's hand provided the design team with an actual plan for the barnyard. The original barn was built at Mount Vernon's Dogue Run farm, three miles from the Mansion. The barnyard complex included two flanking stables with cornhouses appended to each, fenced dung yards, and stock pens - all of which were to be recreated at the four-acre farm site on the Potomac River.

Intensive archaeological excavations of the original site failed to uncover the shallow foundation of Washington's barn - it is likely that the construction of a 20th century swimming pool marred the search. But the discovery of period bricks, thought to have been fired at the original kiln provided useful information on the bricks' size and color. These specifications were used by student interns and a North Carolina firm to create hand-made bricks for the reconstruction.

 The design team also examined other structures at Mount Vernon and buildings of the period that exist at similar 18th-century sites to determine construction techniques.

Physical examinations were also made of structures in Alexandria, Virginia, Washington's hometown, nine miles north of Mount Vernon. The buildings all dated from the period of the Dogue Run barn and confirmed that the lumber available to urban craftsman - and thus to Mount Vernon - was sawn by hand on trestles, not by water-powered mill saws. This helped confirm that the pine frame for the new barn needed to be cut on an old-fashioned pit-saw.

The results of the intellectual exercises were 24 pages of blueprints by Quinn Evans Architects. Using 18th century methods, masons and carpenters began building the replica barn in the spring of 1995. Construction was completed in September of 1996.

Washington's men took twice the time to build the original barnyard complex. Of course, Washington's workers had other things to do - like planting and harvesting the wheat crop that was to be processed in his new, round test barn.